Skim through

What it does: fixative, absorbent

The science

Acrylates crosspolymer-3 is a liquid latex emulsion polymer that combines with carbopol rheology modifiers to produce products with hold strength that can be tailored from normal to ultra-high stiffness.

Benefits for your hair

Promotes styling capabilities

This ingredient helps to increase the styling capabilities of hair by helping it stay in place by inhibiting the hair's ability to absorb moisture. It dries to form a thin coating, which prevents moisture entering.

TLDR 

Acrylates crosspolymer-3 is used to help hair hold its style better by preventing moisture from entering the hair and inhibiting the hair's ability to absorb moisture temporarily.